The data is quantitative abundance of fish and megafaunal invertebrates and algal % cover derived from transect based counts at a wide range of locations across Temperate Australia. The methods are described in detail in Edgar and Barrett (1997). Primarily the data are derived from transects at 5 m depth and/or 10 m depth at each site surveyed. Methods were initially developed for research on temporal changes following protection in Tasmanian long-term MPAs (Maria Is, Tinderbox, Ninepin Point, Governor Island), and the data represented by this record has been collected at Tinderbox. In many cases the dataset involves temporal replication (year scale), particularly for the core Tasmanian MPAs represented by this record.
The underwater visual census (UVC) methodology used to survey rocky reef communities involved quantitative diver-based surveys of fishes, large mobile invertebrates and macroalgae (see below for more detail; also described by Edgar & Barrett, 1997 and Edgar et al., 1997).
At each site, 4 x 50m transects were laid at the 5m or 10m depth contour, and fishes, invertebrates (> 2.5 cm) and algae were recorded separately (as described below) by a team of 2 - 3 divers. Details of each site, including the date and GPS location, were recorded.
FISHES:-The density and estimated size-class of fish species within 5 m either side of the 50 m transect line were recorded by a diver (i.e. 50 m x 10 m). This was done by swimming parallel to the transect line (2.5 m away) and recording fish within a 5 m wide lane, on each side of the transect. Size-classes of total fish length were categorised as 25, 50, 75, 100, 125, 150, 200, 250, 300, 350, 375, 400, 500, 625, 750, 875 and 1000+ mm. Lengths of fish >1000 mm length were individually estimated.
MACROINVERTEBRATES:-A diver searched the seabed for a 1 m wide lane along the transect line for cryptic fishes and macroinvertebrates (i.e. 50 m x 1 m). Four 1 m x 50 m transects were surveyed at each site. Algae were swept away from the transect to obtain a clear view of the substratum. Mobile invertebrates (including rock lobsters, abalone, sea urchins, octopus etc) were counted, as were cryptic fishes (also estimated for size). The maximum shell length of abalone and the carapace length of rock lobsters were measured underwater using vernier callipers whenever possible.
MACROALGAE:-Macroalgae were surveyed at 10 m intervals along the transect line using a 0.25 m quadrat with a grid of 7 wires crossing perpendicularly. Macroalgal cover was assessed by identifying and counting algae species that occurred directly under the 50 (49 plus one corner) grid positions. Values for each species were converted to percentage of the total values for all algal species. Algae were counted in layers, with percent cover of canopy species recorded first, then pushed aside exposing the understorey species for counting.